1. Field of the Invention
This invention relates generally to a means for opening unlatched doors and more particularly to a self-actuating door opener
2. Description of the Related Art
A very common, albeit relatively minor, nuisance associated with many residential buildings is the result of a door which hangs out-of-plumb. Doors can become out-of-plumb due to improper installation or simply the natural shifting of a building over time. Because of gravity, some doors in this condition will not stay open, but rather will tend to swing towards either the closed position or partially closed position. Typically, the operator of a door either wants it fully closed or fully open, but not in-between. Consequently, minor frustration often results when an unlatched out-of-plumb door requires either the use of some sort of door stop or the irritating acceptance of having a door which constantly remains only partially open or sometimes even completely closed (but not latched). This problem may also have other noticeable adverse consequences. For example, some situations require the periodic observation between rooms to monitor children or disabled persons. Additionally, in some situations, ambient ventilation is desired, e.g., in bathrooms or kitchens. In these situations, an unwanted partially closed or completely closed door could become more troubling than merely having a few aesthetic imbalances in the hallway.
Although a variety of doorstops are readily available, they can be somewhat inconvenient to install. Common doorstops require bending over at the waist to apply and remove them, and then afterwards stowing them away from small children and pets when not being used so that they do not get lost. Frequently, the nuisance of this routine causes the operator to either forget or ignore the practice, thereby inviting again the problem of the out-of-plumb door.
Additionally, there are door openers that require a special hinge. A fair amount of time and effort must be expended to replace an existing hinge on the door with the new special hinge to achieve the desired results.
What is desired is a device with a simple one-piece design that can be attached to an existing door hinge pin that automatically maintains either a left-hand or right-hand swing door in the open position without impeding operation of the door. Also, it is desired to have a door opener that can be installed quickly and without the need of special tools or special mounting hardware, and can be manufactured and sold economically. Additionally, it is desired to have a device that can be used in tandem, such as one spring per hinge on two or more hinges within the same door, for increased force.
It is also desired to have a device that utilizes a constant pre-load or partial deflection of the coil to maintain the minimum static tension necessary to actually hold the door open to its desired angle. It is conceivable that some applications may in fact desire the resultant door angle to remain partially open instead of fully open.
It is also desired to have a device that mounts on the door hinge in such a way that it will closely follow the profile of the mating door surfaces and the door hinge, thereby resulting an a relatively undetectable device during normal operations.
A door opener according to the invention includes a helical spring having a pair of legs extending therefrom for engagement with a door and a door frame. One of the legs includes two substantially 90 degree bends such that both legs extend from a first side of the helical spring. Each leg can further include a bend generally midway between the helical spring and a distal end of the leg. Advantageously, the distal end of each leg is substantially straight.
The helical spring can be used with a door hinge including a pair of plates and a hinge pin engaging the hinge plates, wherein the hinge pin includes a hinge engaging portion and a top cap such that the helical spring is positioned around the hinge pin engaging portion so that the legs rest on a top edge of the hinge plates.
In one embodiment, the door opener can be used with a removable safety sleeve, the sleeve configured to be placed over the top cap and helical spring such that the legs are positioned in a groove of said sleeve to maintain the helical spring in a torsional engagement position.
In another embodiment, the door opener can be used with a removable safety hook, the hook including a hole for receiving a first of the pair of legs, and including a channel for receiving a second leg of the pair of legs such that the legs are constrained by the hook to maintain the helical spring in a torsional engagement position.
The invention also includes a method for urging a door into an open position, including removing a hinge pin from a hinge of a door, placing a coil spring over the removed hinge pin, wherein the coil spring has two legs extending radially outward from the hinge pin, and biasing the door into an open position by means of torsional force applied to the door from the coil spring through one of the two legs. In one embodiment, the step of placing the coil spring over the removed hinge pin further includes the step of holding the two legs together by placing a sleeve over the coil spring, wherein the sleeve has a slot into which the two legs are inserted. In another embodiment, the step of placing the coil spring over the removed hinge pin further includes the step of holding the two legs together by placing one leg in a hole in a hook and the second leg in a channel in the hook.